Shortly after Oyo Empire expanded her influence westwards, capturing Port Novo and making Dahomey (present-day Benin Republic) a vassal state pay tributes of 40 guns and 400 loads of cowries and corals regularly to Oyo, of course after phases of wars that made Oyo army a dread to the Dahomeyans, Alafin (Emperor) Labisi appointed a new Basorun (Prime Minister).

To check the Alaafin from becoming too dictatorial, the Prime Minister according to the constitution could pass a vote of no confidence that would turn the Oyo Mesi (Legislators) against the Alaafin and an empty calabash would be handed to the emperor signaling that he was required commit suicide and pave way for a new Alaafin since the Oyo Mesi had lost confidence in his rule.

The Basorun was a high priest controlling all the cults except Sango and Ifa, so this could make him declare that the ancestors and Heavens had lost confidence in an Alaafin. Prior to the appointment of Ga, the unwritten constitution of the empire had been amended from the more ancient style that the Aremo (heir apparent) ruled after an Alaafin passed on.

The new constitution demanded that the heir apparent died with the Alaafin so as to pass on succession without disputes and in a way make the monarchical system a sort of republic. This made Basorun Ga more powerful. Ga became despotic and power drunk and from the slightest accusation that an Alaafin or his Prince disrespected the Oyo Mesi to the accusation that an Alaafin was assuming airs of superiority, Basorun Ga raised five Alaafins to the throne and successively destroyed four of them.

He and his family ruled despotically for twenty years, almost as if they were the Alaafins. By the reign of the fifth emperor, Alaafin Abiodun, the people were fed up of Ga’s dictatorship. On an appointed day, with the support of Are-Ona Kakanfo (Military Commander of Oyo army) Oyabi, the Alaafin and the people broke the jinx of Ga’s powerful magic and rounded up all his family (except Ojo, Ga’s first son) and were seized and killed, Ga himself was burnt to death in his house.

Abiodun’s reign then went on peacefully and lasted from 1774 to 1789, his was a golden reign. However, the center was no longer holding the seams of the Empire together after 20 years of internal imbalance triggered by Ga. Taking advantage of the lawless years, Egba province under the warrior, Lishabi, had proclaimed their independence and migrated towards their present location in Abeokuta. The Egbas had been aggrieved by the oppression of the resident Ilaris (governors) in their three provinces within the empire and the absence of any authority to hold them in check.

When authority was installed by Abiodun, he sent a punitive expedition against the Egbas, but the rocky hills of Abeokuta made the Oyo cavalry failed woefully in subjecting the Egbas. This triggered a domino effect of provinces declaring their independence from Oyo. Even Dahomey had the effrontery to assault Ketu, a westernmost Yoruba district, without fear of the Oyo imperial army. As far as Ewe (in today’s Togo), Oyo began to wane.

''Yorubas generally distrusted Islam in the polity and it is unacceptable according to the constitution for the Alaafin to accept the religion because of its male dominance and autocratic nature of the emirs. Note that women make up part of the Oyo Mesi (Legislators) and there were powerful women like Efunsetan Aniwura who had their say in the polity for Oyo was not totally a male dominated society. Besides, the Alaafin was not allowed to wield total power like the emirs did in the north.''

''Some Yorubas by this time living in Ilorin had also accepted Islam and thus while Ilorin swelled with a platform for its warriors to fight on in one cause, there was no single cause the Yorubas stood for a united fight. The center no longer held and things badly fallen apart. There was no more cavalry for the Oyo army since horses were before bought from northern trade routes which were now closed because of the war against Fulani/Hausa.

The Muslims finally wiped the Oyo capital city after several futile battles on the side of the decimated Yorubas. Oyo’s new capital was now transferred further south to Ago-Oja and a new Alafin, Atiba, was crowned. But by this time, the Alaafin was struggling to maintain a dignity that was lost. Yorubaland became like the Greek city states of Athens, Sparta, Macedonia e.t.c. as Yoruba city states like Owu, Egba, Ijebu, Ondo and Ijesha begun to emerge, with even facial marks emphasizing their differences.

Civil wars became rampant, famine spread like wildfire and slave hunting, slavery before this time was totally alien to the Yorubas since Oyo did not allow any Yorubas to be traded as slave. The slave coasts were now overcrowded with Yoruba slaves as Hausa/Fulani armies slave-hunted in the confusion of collapsed Oyo.

A new war brewed when Ijebu (whose reputation as businessmen is known even till today) and Ife also began to sell refugees from old Oyo as slaves. Owu and these refugees therefore attacked Ife, the sacred city. This turned Ijebu and Ife against Owu.

The Ijebus were the first to employ the use of guns in any battle and thus completely destroyed Owu town. Owu people fled to Egba for refuge where they remain till today in Abeokuta. Ijebu attacked Egba for harboring Owu and a long bitter war ensued between Ijebu and Egba. However, the larger part of these Owu refugees were civilians.

The Owu warriors and other warriors from other destroyed or sacked provinces rather migrated further south and found a settlement in Eleiyele, thus beginning what today is known as Ibadan. Soon it began to attract other warriors who wanted to restore the old glory and because of its position in the rainforest area, Ibadan began to control palm oil belt which was just beginning to replace the trade in human beings.

But still determined to totally expand the Sokoto caliphate downwards by totally conquering the dying embers of the Yoruba influence, the Hausa/Fulani cavalry relaunched another phase of war as they saw New Oyo and Ibadan rising.''